Trout caught in Torch Lake, Mich., are not safe to eat. Groundwater in Baldwin, Fla., is not safe to drink. Six acres of land in Bridgewater, Mass., are not safe to live on.

All three locations were once among the most dangerous toxic waste sites in the country and became part of the Environmental Protection Agency’s Superfund cleanup program. All three are now considered clean by the EPA, though toxins remain.

The EPA is responsible for protecting human health at 1,700 hazardous waste sites across the country through the Superfund program. These sites contain chemicals that can cause a range of serious illnesses, from cancer to birth defects to neurological disorders.

As is the case at Torch Lake, Baldwin and Bridgewater, an EPA “cleanup” does not mean all toxins are gone. Toxic materials, in many cases, are physically or financially impossible to eliminate. Instead, many Superfund cleanups end with restrictions on how a site can be used because the toxins left behind still pose a danger to human health.

Federal funding for Superfund cleanups has stagnated over the past 15 years, even as the number of Superfund sites grows.

America’s toxic waste problem dates back 150 years to the start of the industrial revolution.

In 1962, Rachel Carson’s landmark book, “Silent Spring,” documented the danger of pesticides in the environment to birds, other wildlife and people.

In 1970, the Environmental Protection Agency was created by the Nixon administration, and Congress strengthened the Clean Air Act. Two years later, Congress passed the Clean Water Act.

Then in 1978, Love Canal became international news. Love Canal was a neighborhood in Niagara Falls, N.Y., where homes and an elementary school had been built atop a landfill that was leaking 21,000 tons of toxic waste. Pregnant women there suffered high rates of miscarriages. Babies were born with multiple birth defects.

In 1980, Congress passed the Comprehensive Environmental Response Compensation and Liability Act, also known as the Superfund Law. The goal was to identify and clean major toxic sites such as Love Canal, and when possible to collect damages from the polluters responsible for the contamination.

Today, the EPA estimates that polluters pay for all of or part of the cleanup at 60 percent to 70 percent of Superfund sites. The rest are paid for with federal funds.

There are 1,322 Superfund sites on the EPA’s National Priorities List.

A site is removed from the Superfund list when the potential for causing cancer or other serious illnesses falls to a certain level or is eliminated entirely. In the program’s 34-year history, 379 sites have been removed from the list.